Electrical activity-dependent regulation of the acetylcholine receptor δ- subunit gene, MyoD, and myogenin in primary myotubes

E. K. Dutton, A. M. Simon, S. J. Burden

Research output: Contribution to journalArticle

48 Scopus citations

Abstract

Expression of the skeletal muscle acetylcholine receptor (AChR) is regulated by nerve-evoked muscle activity. Studies using transgenic mice have shown that this regulation is controlled largely by transcriptional mechanisms because responsiveness to electrical activity can be conferred by transgenes containing cis-acting sequences from the AChR subunit genes. The lack of a convenient muscle cell culture system for studying electrical activity-dependent gene regulation, however, has made it difficult to identify the important cis-acting sequences and to characterize an electrical activity-dependent signaling pathway. We developed a muscle culture system to study the mechanisms of electrical activity-dependent gene expression. Gene fusions between the murine AChR δ-subunit gene and the human growth hormone gene were transfected into primary myoblasts, and the amount of growth hormone secreted into the culture medium from either spontaneously electrically active or inactive myotube cultures was measured. We show that 181 bp of 5'-flanking DNA from the AChR δ-subunit gene are sufficient to confer electrical activity-dependent gene expression. In addition, we show that the rate of AChR δ-subunit gene expression differs among individual nuclei in a single myotube but that highly expressing nuclei are not necessarily colocalized with AChR clusters. We also show that expression of MyoD and myogenin are regulated by electrical activity in primary myotube cultures and that all nuclei within a myotube express similar levels of MyoD and similar levels of myogenin.

Original languageEnglish (US)
Pages (from-to)2040-2044
Number of pages5
JournalProceedings of the National Academy of Sciences of the United States of America
Volume90
Issue number5
DOIs
StatePublished - Jan 1 1993

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Keywords

  • denervation
  • gene regulation
  • neuromuscular synapse
  • skeletal muscle

ASJC Scopus subject areas

  • General

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